Description of the Unmet Need
Vision loss is disruptive to the individual affected, their family and society. There are many causes of vision loss and vision impairment. Many of these conditions are treatable.
Age-related macular degeneration (AMD) is a leading cause of irreversible legal blindness in the western world. Over 12 million Americans have some type of AMD, and millions of others suffer from other retina issues. Current home self-monitoring tools for retina diseases fail to adequately indicate a change in vision, resulting in delayed treatment starts and higher incidences of severe vision loss.
Other ophthalmic conditions ranging from refractive error to cataracts to glaucoma also respond to intervention. Unfortunately, many people affected by these disorders suffer needlessly because they are either unaware of their condition or they do not respond to their symptoms with sufficient promptness. This often leads to a delay in presentation after the onset of a visual change, which creates a delay in clinical diagnosis and therefore a delay in the start of treatment, which may lead to permanent and unrecoverable vision loss.
The novel concepts described herein boost patients' ability to accurately and confidently self-monitor their vision in a home environment, which enables improved recognition of symptoms, which drives proper help-seeking behavior, which enables acceleration of presentation to an eye care specialist, which enables earlier clinical diagnosis of onset or progression of disease, which enables earlier start of treatments, which leads to fewer people losing vision.
The Amsler and Yanuzzi grids, the only widely used self-tests for AMD, have proven largely ineffective at enabling patients to recognize the signs that they should consult their retina specialist for treatment. There are no other commonly available tools for patient self-monitoring in one's home between office visits. The Amsler Grid has been in use and largely unchanged for more than 60 years. Shortcomings of the Amsler grid include but are not limited to: periodicity of the test pattern, lack of individual adjustment, lack of visual & memory stimulating triggers, inability to overcome the visual completion phenomenon, poor compliance, subjectivity, lack of quantification, anxiety and doubt, relatively high levels of concentration required and habituation.
With respect to refractive error, cataracts, glaucoma and other vision disorders, a good assortment of educational literature and information is available from doctors as well as over the Internet. However, the problem of late presentation persists and it is evident that there is a gap in the marketplace for novel solutions that deliver educational messages and self-monitoring tools that can help accelerate patient presentation for all forms of vision loss.
While the dry form of AMD progresses slowly over years, the wet form of AMD progresses rapidly and can mature from a nascent stage to legal blindness in fewer than 12 months. Studies have shown that typical wet AMD patients can take 6 months to present after the onset of symptoms. Thus, annual vision check-ups are not sufficient to protect patient's visual health; and diligent home self-monitoring is essential. However, the current grid tests do not provide effective self-monitoring. The result is that many people are needlessly suffering advanced vision loss and blindness because they lack the ability to accurately and confidently monitor their vision and know when to accelerate their visit to their eye care professional before their scheduled appointment date. By waiting until their routinely scheduled exam date or not presenting until vision loss impacts activities of daily living, people put their visual health at risk.
Studies have also shown that anti-VegF treatments for wet AMD are more effective the earlier they are started. Earlier presentation, therefore leads to lower initial vision loss, improved therapeutic outcomes and a greater likelihood of maintaining or restoring remaining vision. Each day that a patient delays the start of treatment may lead to worsening and often irreversible loss of vision.
In clinical testing, the Amsler grid has not proven successful at enabling patients to detect issues nor to understand when to seek council of their retina specialist. The following references are made to the scientific literature:
Referencing: Schuchard, Arch. Ophthalm 1993 vol 111 no. 6
“For scotomas of 6 degrees or less in diameter, 77% of standard and 87% of threshold scotomas were not detected by Amsler grid testing.” “Amsler Grid reports have poor validity and cannot be accurately interpreted for use in the clinical diagnosis of retinal defects.”
Zaidi, et al, Eye, May, 2004
“The surveillance protocol detected less than 30% of the specific patients who subsequently underwent laser treatment.” “Bearing in mind the prevalence of AMD and the increased therapeutic importance of early detection of SRN, it is clear that improvements in the current surveillance protocol are required.”
Achard, et al, Am J Ophthalmol. 1995
“Results of two successive Amsler grid tests were not comparable, even when the technique was identical and time between tests was no more than 2 to 15 min.” “the Amsler grid technique is unreliable for evaluating central scotomas.”
A variety of reasons have been put forward by these studies to explain the reasons behind the poor performance of the Amsler grid:
Schuchard, Arch. Ophthalm 1993 vol 111 no. 6
“The perceptual filling-in of patterns such as the Amsler grid and fixation characteristics have a major influence in the result of Amsler grid testing.”
Zaidi, et al, Eye, May, 2004
“ . . . difficulty with compliance . . . ”, “ . . . problems with the subjective nature of the test.”, “Relatively high levels of concentration are needed to undertake the test . . . ”, “ . . . levels of fatigue and anxiety are important,”, “ . . . compounded by the perceptual completion phenomenon . . . ”
Achard, et al, Am J Ophthalmol. 1995
“Our data corroborated Schuchard's observations regarding the relatively poor sensitivity of Amsler grid tests.”, “Additionally, our study further characterized the completion phenomenon found when Amsler grid tests are used and emphasized the rapid changes that occur in completion over time.”, “It cannot be excluded that the changes in results over time were partly because of changes in fixation position.”
This research is corroborated by the inventor's general conversation with retina patients. In interviews, the following assertions regarding the Amsler are supported by patient observations:                1. Poor compliance with test protocol—many neglect to do any testing        2. Confusion regarding purpose—many did not know why they were given the Amsler        3. Confusion regarding baseline & monitoring—none knew they were supposed to monitor their vision over time        4. Confusion regarding proper usage—several reported looking for “moving” or “changing” lines as if they expected to see motion on the card as the symptom of further disease        
Patients delay for multiple reasons. Many patients are simply unaware of the onset of a problem; this frequently occurs when the onset occurs in the non-dominant eye or in patients with a high degree of blur tolerance. Many patients are aware of their symptoms but don't have confidence in their self assessment to consider the changes to be significant; this leads them to question whether their vision is truly different than it was last week or the week prior allowing slow progression of vision loss to continue without triggering a help-seeking response. Many patients are aware of their symptoms and have confidence in their self-assessment but incorrectly attribute the problem to a less severe cause such as simply needing new glasses or the progression of cataracts. Many patients are aware of their symptoms and have confidence in their self-assessment but do not respond with urgency, perhaps hoping vision will restore itself and simply waiting until their next scheduled eye exam to discuss the anomaly with their doctor; this can lead to situations where patient's inability to make a decision about seeking help wait until a dire consequence of functional blindness before they feel the urgency to decide to seek help. Many patients delay out of an inability to arrange an appointment with an eye doctor, either because of transportation issues, inability to master reimbursement questions, the need to attend to higher morbidity diseases, lack of a relationship with an eye care specialist, and others.
Lack of confidence in self assessment can frequently be attributed to shortcomings in the standard of care in home vision monitoring—the Amsler grid. In the inventor's personal experience as a wet AMD patient for over 10 years, the Amsler grid has shortcomings in further areas, including but not limited to:                1. Difficulty in detecting changes to vision especially subtle changes        2. Difficulty in locating the periphery of the affected, scarred or damaged retinal area        3. Difficulty in detecting changes to the size or complexion of an affected area        4. Difficulty in establishing a benchmark viewing distance        5. Difficulty in locating and/or maintaining a gaze at the center of a grid without wandering        6. Difficulty in remembering the exact limits of an affected area        
The impact of these diagnostic shortcomings include but are not limited to:                1. Substandard identification of newly affected areas (of the retina)        2. Incorrect or missing identification of newly affected areas        3. Substandard assessment of size and complexion of affected areas        4. Lack of confidence in daily measuring        5. Frustration with the assessment process        6. Variation in day-to-day assessment of the overall size and complexion of an affected area        7. Anxiety regarding uncertainty of whether the vision loss is getting better or worse        
The consequences of these impacts can lead to (but are not limited to) unnecessary delays in presenting to an eye care professional.
The implication to the eye care industry are many:                1. Fewer patients receive intervention at the earliest stages of disease (drug therapy, corrective lenswear, surgery, etc)        2. Fewer patients fall within the treatable range of the disease because many have progressed beyond acceptable treatable limits for first-line therapies, reducing the armamentaria available to the treating physician        3. More patients fail to receive full benefit of their treatment, some find the treatment ineffective because they started late, and many lose significant vision        4. Certain therapies that are used in late-presenting patients may not establish optimal health outcomes if compared to a scenario where more patients presented days or weeks earlier        
Societal implications include, but are not limited to:                1. Vision loss directly reduces a patient's ability to be a productive contributor to society        2. Vision loss indirectly taps patient's family's ability to productively contribute to society        3. Vision loss increases the need for social services and other governmental support        4. Delayed presentation increases the extent of treatment required, increasing the monetary costs through public & private insurance programs        
The novel ideas and approaches enclosed will benefit others by giving them more accuracy, simplicity and ease in the monitoring of their vision. As a result, monitoring will be performed more regularly, with better adherence and higher accuracy and confidence. And thus, any necessary treatments will be delivered as soon as practical thereby increasing the chances for best treatment results and reducing the risk of vision loss and blindness.
Background Info—the Use of Acuity Testing such as Near Vision Acuity Testing
In traditional vision care, an eye care professional will measure near vision acuity in the exam room with a small semi-rigid card with printed indicia comprising the test characters. The patient will hold the test and read the content of the test to their best ability. Many acuity tests, such as the near-vision Snellen have a series of letters or symbols with common character size on each row. Each consecutive row has a smaller font size. By maintaining a consistent distance between the eye and the test and knowing the size of the characters used, one can get an indication of near vision acuity for each eye. Use of standardized sized characters at a measured distance in a properly lit area allows for absolute vision measurement and a clinical diagnosis of acuity.
When testing near vision acuity, the eye care professional may measure the distance between the test and the patient's eyes, or there may be a string attached to the test to enable the patient to hold the test at a fixed distance.
In a home environment, a critical measure of the effectiveness of any tool is the patient's ability to adhere to a testing regimen over multiple years. A home testing system loses its value when patients stop using it. Few patients have the patience to measure the distance between their test and their eyes each time they use a test. Samples of patients who have been interviewed have stated that they find use of a string to maintain proper distance as being cumbersome. A trade-off exists regarding whether to force patients to measure or maintain precise distance between the test and the eyes and risk poor compliance, or to allow patients to use a test without use of distance tools and hope to maintain compliance over many years.
Novelty within the system herein recognizes this trade-off and does not request patients to measure the vision between their eyes and the test or request patients to use a string to maintain a fixed distance.
In observing patients, especially those over 60, one can recognize that the effects of presbyopia have rendered most people with a narrow band of distance between the eyes and the reading article where acuity is optimal. Patients often extend the reach of their arms to help enable them to focus on small print. The lens of the eye loses flexibility with age, and patients are thus left with only a narrow range of distance that is usable for reading fine print.
When reading fine print—as with a near vision acuity test's lower limits, patients, especially those over 60, have a limited range of distance where they hold their reading materials. After a patient has reached their 60's, this range of distance does not vary greatly from year to year. This distance will vary from patient to patient and with the nature of corrective lens-wear selected. Thus, while this distance may not easily facilitate an absolute measure of vision, its consistency week over week is sufficient for conducting relative vision measurements.
For patients who are able to read fine print at a variety of distances, tests can include a component that alerts people that a change in distance (bringing the test closer to the eyes) is also a symptom of acuity loss. Thus, the instructions to patients can alert them that a change in acuity may be detected by either a significant change in the character size that can be read and a significant change in the distance used to hold the test object. This enables relative vision monitoring when using near vision acuity tests with variability of reading distance between three and thirty inches between the test characters and the user's eyes. Thus a change in reading distance becomes the determination of vision change.
In a clinical setting, once the near vision acuity test is completed, the acuity testing device is subsequently handed back to the eye care professional and maintained as part of the office equipment. Results of the test are documented in the patient's chart. The patient is not provided with any facility to observe or monitor their acuity between office visits. The patient's acuity is used as a pure clinical measure and not typically as a home monitoring measure.
Background Info—Acuity Type Test Together with Grid Tests:
The purpose of a home vision monitoring test is to enable patients to recognize changes in vision and when there is a change in vision to take help-seeking action to minimize the time between the start/worsening of a vision problem, such as a retina problem, and presentation to an eye care professional. The Amsler Grid is a commonly used home monitoring test that patients can observe and help detect a change in their vision. A near vision acuity test, such as a small font Snellen-like test, can be used in the home. Augmenting a grid test with a secondary test such as a near vision acuity test may provide additional benefit for diagnosing & monitoring retina health as well as diagnosing and monitoring other vision problems.
Providing a reduced-font Snellen-like test for in-home use may have limited ability for the test to yield an absolute (ie: clinically repeatable and accurate) measure of acuity (because of variations in printing size, variations in the space between the eye and the test, inconsistency in use, improper lighting, improper use, etc). However, gaining an absolute measure of acuity is not necessary in order to have a successful monitoring tool. Observing a significant difference from one test (perhaps a baseline test) and another test conducted days/weeks/months in the future provides the user with an ability to compare two readings and look for a relative change between the two vision tests. To the extent that a patient can maintain consistency in their observations, a non-absolute measurement is sufficient to help a patient recognize a change in vision that may need to be brought to the attention of his/her eye care professional.
The Challenge of Near-Vision Acuity Tests in Monitoring
Unfortunately, the success of a patient's ability to evaluate a change in near vision acuity is dependent upon the patient's ability to compare a current reading with a reading taken at an earlier date. Without a facility for documenting a patient's near vision acuity, the patient must rely upon their memory as the means of comparing. The letters offered in a typical near-vision acuity test are offered in a way as to prevent memorization and do not spell a word or offer a pneumonic assistance. And, the label associated with each line of vision is often printed discretely to minimize distraction, which prevents it from being used as an easy tool to help remember one's reading test result.
Consequently, near vision acuity tests such as reduced font Snellen-like tests pose a challenge in implementation for successful use in monitoring vision over time.